In agricultural planting, it has been found that crop rotation increases the ability to produce maximum crop yield. A corn and soybean rotation has been found to be one of the most common and profitable crop rotations. It also has been determined that the row spacing for maximum profit per acre is different for these two crops. Soybean crops produce better yield when planted in narrower rows than corn crops. For instance, the recommended and most commonly used row spacing for soybean crops is in the range of about 10 to 15 inches and the range for corn crops is about 30 to 36 inches. Moreover, not only is soybean yield increased through narrower rows, but weed control costs also are reduced because narrower rows are found to canopy much quicker than wider rows. Thus, it is very important that crops be planted in rows utilizing the known spacing for that particular crop to produce maximum yield.
Due to the known yield benefits from different row spacing between rotational crops, coupled with the high costs associated with farm implements, farmers typically are faced with a serious problem when deciding which type of implement to purchase for rotational type planting. One known solution has been to simply purchase separate equipment for each type of crop. For instance, one would purchase a conventional planter adapted for corn planting and another drill type planter adapted specifically for planting soybean crops in narrower rows. For most farmers, this is an undesirable option. Not only is this solution expensive in that it requires purchasing of two separate implements, experience has revealed that drill type planters do not populate planting as accurately as the typical conventional planter units. Thus, it commonly is preferred to use a conventional planter for planting both corn and soybean crops.
Some available planters, such as the 7100 John Deere planter, are capable of being mounted with additional planter units between the existing units to effectively reduce the row width by one half. More specifically, to plant narrower row crops, additional planter units can be mounted directly to the main tool bar in between the existing units because this space is unobstructed so to provide direct access directly to the main tool bar of the planter. For instance, a 10 unit planter set for 36-inch rows for corn crop planting could be converted in this manner to a 19 unit planter with reduced 18-inch rows by inter-mounting additional planter units for soybean crop planting. While this does not meet the desired spacing of 10 to 15 inches between rows, it has been an acceptable solution.
With other larger planters, such as the John Deere 7000 front fold planter, mounting of additional planter units between the existing units is not a viable option because this space is occupied with lift wheel assemblies for raising and lowering the planter. More specifically, a number of lift assemblies occupy the space between a number of the existing planter units and include components that extend above the main tool bar. As a result of these lift wheel assemblies, it is impossible to mount additional planter units directly to the main tool bar.
One known device directed to accommodate for planter lift wheel assemblies is a product referred to as the Wetherell Inter-Plant Bracket by Wetherell Mfg. Co. The Wetherell bracket consists primarily of a two member bracket system in which one member mounts directly to the main tool bar at the existing planter unit and angles into to the space between that planter unit and an adjacent existing planter unit and the second member connects to the first and carries an additional planter unit. In addition to angling laterally in between the existing planter units, the bracket also rises up and over the lift wheel assembly.
While the Wetherell device accomplishes providing additional planter units on planters with lift wheel assemblies between the existing planter units, a known shortcoming is the tendency to place increased stress on the bracket due to its angled reach between existing planter units. Accordingly, the bracket is made heavy and cumbersome to provide the necessary durability to support the additional planter unit during planting.
An additional shortcoming is that the two members of the bracket are joined with a number of bolts and, therefore, do not facilitate quick attachment and detachment of an additional planter unit for converting between wide and narrow row spacing. Experience has revealed that the time necessary to attach and detach the second member carrying the additional planter unit is unduly increased due to the bolt attachment. In fact, it has been found that to efficiently mount the planter unit with the Wetherell bracket it often takes more than one person to locate the planter unit, align the second bracket member with the first member and install and tighten the bolts. Moreover, since the Wetherell bracket is an angling bracket system, there is the need for brackets angling to the right and to the left for most conventional planters to narrow row spacing.
Thus, there is a desire for a more sturdy and reliable system for converting a multi-row planter quickly and easily between wide and narrow row spacing to facilitate efficient and effective crop rotation. The design must be capable of accommodating lift wheel assemblies and be sufficiently durable to withstand the rough terrain of typical fields. It also must be reliable to ensure accurate planting. Moreover, many planters include a number of planter units carried by wings that fold forward and inward for transport. The system also must be capable of mounting additional units to these wings in a manner that does not drastically increase the transport width.